This image is part of a series that was created for an open textbook, Cell Biology, Genetics and Biochemistry for PreClinical Students. The textbook will be available Late 2021.
Kindred Grey (2021). "Metabolism of methionine."CC BY 4.0.
Circular diagram homocysteine arrow enzyme homocysteine methyltransferase with N5-menthyl-THF arrow THF to methionine arrow enzyme methionine adenosyltransferase with ATP arrow 3 Pi to S-adenosylmethionine (SAM) arrow enzyme methyltransferases with loss of CH3 (used for methylation) to S-adenosylhomocysteine (SAH) arrow enzyme S-adenosylhomocysteine hydrolase to adenosine dotted arrow to nucleotide salvage. Homocysteine arrow enzyme cystathionine β-synthase with serine addition to cystathionine arrow enzyme cystathionine ᵞ-lyase with loss of α-ketobutyrate to cysteine arrow enzyme cysteine dioxygenase with O2 addition to cysteine sulfinate arrow enzyme cysteine sulfinate decarboxylase with loss of CO2 to hypotaurine arrow enzyme hypotaurine dehydrogenase with NAD+ arrow NADH to taurine arrow bile salts. Cysteine sulfinate bidirectional arrow enzyme transaminase with α-ketoglutarate bidirectional arrow glutamate to β-sulfinylpyruvate arrow with loss of sulfite to pyruvate. Sulfite arrow enzyme sulfite oxidase to sulfate. Threonine arrow enzyme threonine dehydratase with loss of NH4+ and H2O to α-ketobutyrate dotted arrow text (in mitochondrial matrix) to succinyl-CoA dotted arrow TCA. Cysteine dotted arrow glutathione, coenzyme A